Infants with congenital heart defects (CHD) demonstrate impaired ability to regulate autonomically controlled neurobiologic processes, such as those revealed in feeding and arousal. An impaired ability to regulate neurobiologic processes compromises infants' capacities for physical growth and maintenance and may have long-lasting effects on regulation of social and emotional behavior. The quality of interactions between mothers and infants may affect neurobiologic regulation. This study is designed to describe the relationship between maternal feeding behaviors and physiologic regulation and regulation of arousal in infants with CHD. The long term goal of this research is to identify specific maternal behaviors that contribute to physiologic regulation and regulation of arousal in these infants and to develop interventions directed at supporting mothers in interacting with their infants in ways likely to enhance this critical function. Because each type of congenital heart defect has unique functional and physiologic characteristics, this study will be limited to infants with transposition of the great arteries, one of the most common CHDs. The specific aims are: (1) to describe infant physiologic regulation and arousal during feeding and (2) to examine the effect of mother's feeding behavior on infant physiologic regulation and arousal. Data will be collected during the immediate post-operative period and again two weeks later in order to capture early patterns of maternal behaviors and their association with physiologic regulation and arousal during feedings. Heart rate variability (HRV) will be analyzed and used as an index of physiologic regulation. Infant state during feeding will be used as an index of regulation of arousal. Videotapes of infant feedings will be examined to identify maternal task and social-emotional-behavioral competencies. Multilevel modeling will be used to model patterns of HRV change within feedings and over time, and to examine maternal feeding behavior as a predictor of HRV and arousal. This research will provide important information about how interactions between mothers and infants with congenital heart defects influence the infants' physical, emotional, and social outcomes. This knowledge will be used to develop interventions to assist mothers in establishment of patterns of caregiving supportive of their infant's development. [unreadable] [unreadable] [unreadable]